42 G Proceedings. 



And I might add here another important peculiarity in these two main 

 divisions, which was firsb pointed out to me by Mr. Fuller, and which is of 

 great practical value when examining even the smallest bones. Mr. Fuller has 

 found that in the mere handling of the bones a great difference is at once to be 

 detected amongst those coming from the very same spot. Thus the remains of 

 Palapteryx are harder, and have i-esisted more effectually the influence of time 

 than those of Dinornis ; the exterior dense crust is far stx-onger and thicker 

 and is less smooth than in the latter. Moreover, the bones of the Palapterygidoe 

 are not quite so porous as those of the Dinornithidse, and consequently are 

 heavier in proportion. 



After these fev^^ introductory observations I now proceed to lay before you 

 the scheme after which I propose grouping together the different species of 

 our extinct struthious birds, giving, at the same time, some of the principal 

 distinctive features of each group : — 



A. Family Dinornithid^. 

 a. Genus Di7iornis. 



Metatarsus long, no hallux, pelvis narrow, sternum longer than broad, 

 convex, with constant and well-marked coracoid depressions for the scapulo- 

 coracoid bone ; narrow and sti'aight anterior crest, costal processes slightly 

 developed, lateral processes standing at less angle than in the Palapterygidas. 

 Existence of a bony scapulo-coracoid ; beak narrow and j)ointed, three inter- 

 costals ; skeleton altogether of a more slender stature than any of the 

 Palapterygidse. 



1. Dinornis maximus. 



2. Dinornis rohustus. 



3. Dinornis ingens. 



4. Dinornis struthioides. 



5. Dinornis gracilis. 



b. Genus Meionornis.* 

 Metatarsus long, no hallux, pelvis narrow like Dinornis, and the Avhole 

 skeleton altogether more slender than any of the Palapterygidse. Sternum 

 convex, longer than broad, with a broad and well-curved anterior border ; 

 costal processes well develoj)ed, no coracoid depressions ; bony scapulo-coracoid 

 absent, beak well pointed and even narrower than in Dinornis. 



1. Meionornis casuarinus. 



2. Meionornis didiformis. 



B. Family Palapterygid^. 

 a. Genus Palapteryx. 

 Metatarsus very short and broad, with hallux and hind toe ; distal trochlece 



* From melon, less ; and omiti, bird. 



